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Understanding the Different Types of Multiple Sclerosis


What Causes Multiple Sclerosis?

No one knows what causes multiple sclerosis. Tantalizing clues have sparked research in many areas but no definite answers. Some theories have included:

  • Geography. People in the northern U.S. develop MS more often than those in the warmer south. Research into vitamin D and sunlight as protective factors is ongoing. 
  • Smoking. Tobacco may increase the risk slightly. But it's not the whole story. 
  • Genetics. Genes do play a role. If an identical twin has MS, the other twin has a 20% to 40% chance of developing it as well. Siblings have a 3% to 5% chance if a brother or sister is affected. 
  • Vaccines. Extensive research has essentially ruled out vaccines as a cause of MS.

Multiple sclerosis is probably an autoimmune disease. Like lupus or rheumatoid arthritis, the body creates antibodies against itself, causing damage. In MS, the damage occurs in the lining, or myelin, of nerves.

How Is Multiple Sclerosis Diagnosed?

Multiple sclerosis is generally diagnosed after a person has experienced troublesome symptoms related to nerve damage. Vision loss, weakness, and loss of sensation are common complaints.

The most common tests used to diagnose MS are scans of the brain and spinal cord with magnetic resonance imaging (MRI) and lumbar puncture or a spinal tap.

Unfortunately, the time between the first appearance of symptoms and diagnosis of MS can be prolonged. Studies show that because symptoms are often low-grade or vague, doctors may miss the diagnosis.

Even when symptoms are definitely consistent with MS, the diagnosis still can't be made right away. This is because, by definition, multiple sclerosis is a long-term illness. After the first symptoms, there's an often frightening and frustrating period of waiting until more symptoms occur and the diagnosis becomes clear.


WebMD Medical Reference

Reviewed by Varnada Karriem-Norwood, MD on June 05, 2013
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